Electric welding apparatus



(No Model.)

2 ShLeets-Sheet 1. H. LEMP.

ELECTRIC WELDING APPARATUS.

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(No Model.) 2 Sh'eetsSheet 2.

H. LEMP. ELECTRIC WELDING APPARATUS.-

No. 443,224. Patented Dec. 23, 1890.

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IIERMANN LEMP, OF LYNN, MASSACHUSETTS, ASSIGNOR TO THE THOMSON ELECTRIC \VELDING COMPANY, OF MAINE.

ELECTRIC WELDING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 443,224, dated December 23, 1890.

Application filed August 6, 1890. Serial No. 361,162. (No model.) I

To all whom it may concern: number of contacts through which the cur- Be'it known that I, HERMANN LEMP, a citirent flows,I avoid twoimportant objections zen of the United States, and a resident of namely, the nice and careful construction of Lynn, in the county of Essex and State of sliding contacts and the necessity of making 55 Massachusetts, have invented certainv new the current-carrying devices of heavy conand useful Electric \Velding Apparatus, of struction in order to stand the wear and tear which the following is a specification. of usage.

.My present invention relates to the con- A noticeable difference between the style struction of that class of electric metal-workof clamps heretofore used and my construc- 6o 10 ing apparatus in which the work is heated by tion is in the relation between the currentthe passage of an electric current and movecarrying devices and the clamps for holding ment is given to the work while heated in the the bars, rods, 850., while under longitudinal welding, upsetting, or other operation. pressure, and also in the relation of the metals The general form and operation of the maworked upon to the current devices. In the I5 chines used in electric welding, brazing, forgold style of welder the pressure was applied ing, upsetting, &c., are fully described in and to the end of the slide before mentioned, thus will be readily understood from various patmaking it serve both as current-clamp and cuts granted to Elihu Thomson on this subpressure-clamp. ject, and it will therefore be unnecessary to In my present invention, instead of secur- 7o 20 explain the process or that apparatus; but in ing the stock to copper blocks or pieces slidorder to show more clearly the advantages of ing upon other blocks, I slide the stock itself my construction I refer briefly to particular past suitable current-carrying electrodes or parts of the machine as used in the operation contacts bearing on the stock and which reof welding. It is well known that this promain stationary, and provide independent 7 5 2 5 cess of welding is generally a butt-welding mechanical jaws or clamps which grasp the one, although it is not by any means confined stock and serve to hold it, so that end pressto that, and that longitudinal pressure isap- 'ure may be applied. By this arrangement plied to the metals to force the abutting ends the current-carrying clamps need be only together at the time when the current has large enough to carry the current without 0 caused the metal to become very hot and heating. While I prefer to use separate menear or quite at the fusion-point. In-most chanical jaws or clamps for holding the stock cases this pressure is applied while the ourin place in the operation of applying end rent is still flowing. Consequently it is necespressure, it would be within my invention to sary to have some means of carrying the curmove the stock past the current-carrying 3 5 rent to the metal at the same time that it is clamps or electrodes by any means, as by moving. Heretofore this has been done by hand. providing two parts with smooth'polished sur- The great advantage in the use of such defaces, one sliding on the other, the metal to vices as are herein mentioned is that the be worked being clamped upon the sliding wear and tear is principally upon parts which 0 0 one and a connection made between the other are easily and cheaply replaced and not upon and the source of current. This necessitated surfaces which are not only difficult to make, very fine mechanical construction of the surbut which must be kept in perfect condition faces in order to lessen the resistance at that in order to Work to the best advantage; also, point and avoid loss of power during the flow the liability of the several parts to heat and 9 5 45 of heavy currents. In working with heavy warp is greatly reduced, as is also the cost of metals or large masses of metals too fine conconstruction and maintenance. struction is incompatible with the rough usage In the accompanying drawings, Figure 1 that such a machine receives, and in time the illustrates a type of machine formerly emparts become worn and bent out of shape, ployed. Fig. 2 shows in perspective a form 5 so that new fittings are required. Although of machine embodying my present invention. in my new construction I do not lessen the Figs. 3, l, 5, and 6 are details of construction of the clamp and current-carrying electrodes bearing on the work. Fig. 7 is a side elevation of another form of electric metal-Working apparatus wherein a rubbing or sliding contact between the work and current hearing or carrying electrodes in direct contact therewith is provided for in the operation of retating the work while included in the electric circuit. Fig. 8 is a cross-section through one of the uprights bearing the electrode or plunger which bears upon the work. Fig. 9 is an end view of the plunger. Fig. 10 is a side elevation of a plunger in which provision for water circulation is made in a modified way.

In Fig. 1 1 is the secondary of an alternating-current transformer. It is formed as a copper casting with a groove in it to hold the primary coil, the iron core passing through the opening in the center. This arrangement of the three parts is illustrated in Fig. 2. Referring to Fig. 1, i2 is a V-block, in which the bar or rod constituting the work is securely held by the gripping device 3. A red connects the lever with the V-block, and this provides the means for longitudinal pressure. This clearly illustrates how the current is collected from the secondary and given to the stock, and also shows how easy it is for the V in the secondary to become dirty or coated with grit, which impairs the contact and causes heating when the large currents flow which are used in the work.

Referring now to Fig. 2, i is the secondary, the primary, and (3 the iron core, of a transformer. 7 is an upright projection on a terminal of the secondary, and which is preferably an integral part of the casting which forms the secondary. 7" is a copper casting of the same form and dimensions as 7, but is capable of being slid on the casting and fastened in any position by means of the screws 8 and 8*. The object of making this movable is to get variations of projection of the stock beyond 7 and 7, according to the diameter of the bar welded, a feature indispensable with good rcsultsin welding by electricity; otherwise this part might be stationary, and is so during the welding operation. 9 is a steel plate with side guides, which is fastened to but insulated from i. 10 is an ordinary centering-chuck, which slides 011 the plate and in the guides and grasps the work. Any other device might be used for grasping or clamping the work to give it. end movement. 10 is another centering-chuck, which is insulated from '7, but is secured to that casting, so as to move with it when required. It will be noticed that the difference between the right and left sides is this, that 1.0 may change its position with regard to '7, which is stationary, and that 10 does not change its position with regard to 7, but is moved with it. It is to be understood that I do not limit myself to this precise me chanical construction, as in some cases it is desirable to move both chucks toward each other at once, in which case both sides would be alike, and it may be found convenient to use an entirely different form of mechanical chuck.

The construction of the part 7 and 7 is illustrated in the other figures. From the inside surface of the round hole in these parts and extending radially outward are made three holes equidistant apart, or in other cases more or less than three may be required, and I do not limit myself to any special number. ()no of these is shown at 11 in Fig. it. Extending the length of these holes and leading into them from the face of the casting are slots 12 and 12", Fig. 2). Fitting into the hole 11 is a copper rod 13, backed by a spring 1-1, which tends to force the rod toward the cen' ter of the large hole, so as to bear upon and make electrical connection with the work, as bar 18 or 18. Steel pin 15 is put through the slot 12 and screwed into the piece 13, allow ing the latter to be moved upward by any external means. 16 is a cam rotated by the handle 17 on a collar surrounding the large hole, and serves to move all three pieces 13 13 123 upward by bearing against the steel pins until these pins rest on the projections of the cam, holding the rods 13 in a position farthest away from the center. This position is shown. by the dotted lines. \Vhen the handle is moved to the position shown by the full lines, the springs force the rods toward the center to the position shown by the full lines, Fig. 3. Another means of accomplishing the same end is illustrated in Figs. 5 and 6. In this instance the holes containing the rods 13 are connected from the outside to a source of pneumatic or hydraulic pressure, which may be made to force the three pieces toward the center or upon removal of the pressure to allow the rods to move back, each rod acting as a piston would.

The operation of the machine is as follows:

Referring again to Fig. 2, if two bars are to be welded, I start first with the contactpieces or current-bearin g electrodes 15 moved outward and jaws of the mechanical chucks apart, and then push the bars 18 and 18 through until their ends abut against each other half-way between the parts 7 and 7, when the jaws are closed tightly upon the bars. The handles 17 and 17 are now moved to allow the rods 13 to come down on the bars and make contact with them. As the mechanieal chuck is. insulated from the secondary of the transformer, it is evident that the entire contact for the flow of current is made by these three pieces, which bear down rather hard by reason of the pressure behind them. As the current heats and softens the abutting ends, the rods are forced together by means of any mechanical pressure, as by pressure acting on pistons, the bar 18 sliding on the three contact-rods 123. The noticeable difference between this action and the one illustrated in Fig. 1 is that the distance be tween the contacts representing opposite polarity remains the same in the former, while in the latter it decreases as the longitudinal pressure forces the bar together; but the principal advantage to be observed is that there are no sliding surfaces which must be kept in perfect order free from dirt or grease, the. The contact-pieces used are so simple and cheap that they may be easily replaced when worn out. Also, by using a number of contacts arranged in a circle or around the stock I obtain a better distribution of the current, especially onlarge work.

In operations, especially upsetting and subsequent forging or shaping, it is desirable to rotate the metal bar or rod in order to apply dies orproper cutters. In Fig. 7 is shown the application of my invention to an apparatus suitable for this purpose 19 represents the bed or base of a lathe, which is made in, two parts insulated from one another. The usual cone-pulley 20 and chuck 10 are insulated from the base, as is also the tail-stock. This tail-piece 21 carries a chuck 10 which is rotatably mounted, and may revolve when a bar or rod, as 18, is held by the two chucks and power applied to pulley 20. The uprights 7 and 7 are the same in construction as in Fig. 2, and are electrically connected with a source of current of large Volume. This may be done by connecting cables 23 and 23 to the two insulated parts of the base of the lathe and mounting the uprights upon the base, as shown, allowing them freedom of movement, for the same reason as in Fig. 2. For this purpose the screws 24 and an are provided to clamp the uprights when in the proper position. The screw 22 provides end pressure for a welding or upsetting operation. In such an apparatus the contact-- pieces contained-in the uprights 7 and 7 bear upon and make contact with the bar-in the same manner as shown in Fig. 2. The friction of the rotating bar will add to the heat caused by the large amount of current flowing from contact to bar, and therefore I apply a cooling-fluid to the contacts in accordance with a patent granted to Elihu Thomson, No. 317,142, and as shown in Fig. 8. 7 represents part of one of the uprights, as shown in Fig. 5. The contact-piece is made of two concentric tubes 26 and 27, the outer one forming a hollow stem or support terminatingin a contactblock 28. The inner tube passes through the piston 25, (see also Fig. 9,) leaving a small passagefrom the top of the cylinder to the bottom by means of the two tubes, all as shown. A plug 29' closes the lower part of the cylinder after the contact and piston are in place, and an outlet 30 communicates with that end of the chamber.

lVhen hydraulic pressure is admitted to push the contact downward, as before explained in connection with Fig. 5, a certain amount of water escapes through tube 27, dashes against the end 28, and passes out through tube 26, the holes through the bottom, and outlet 30. This keeps the contacts cool. Another method is to drill asmall hole through the whole length of a solid contactpiece, like that shown by 13, Fig. 5, and let a small amount of water flow out the end and onto the bar. Such a contact-piece is shown in Fig. 10, the dotted lines representing a small passage through the center. This latter is in accordance with an application made by me and filed in the Patent Offlce May 31, 1890, Serial No. 353,809.

I do not limit myself to the particular forms of machine shown and described, as I may use various mechanical variations in the details of the mechanism without departing from the spirit of my invention.

I am aware that welding-machines have been made and patented in which solid me chanical construction was used to take any strain from the electrical devices made separate from the same but these involve either flexible connections,which are not practical in heavy work, or separate sliding contacts,which it is the purpose of my invention to avoid.

What I claim as my invention is- 1. In an electric metal-working apparatus, fixed current-bearing electrodes making contact with the work and through or by which the work slides in the welding, upsetting, or other operation, as and for the purpose described.

2. In an electric metal-working apparatus, plungers or current-carrying electrodes working in lines converging upon the work, and means for moving the work between said plungers at right angles to the line in which said plungers move.

3. The combination, in an electric metalworking apparatus, of a current clamp or electrode bearing on the work, and a mechanical clamp for grasping the work and moving it by the currentclamp, as and for the purpose described.

4. The combination, in an electric metalworking apparatus, of current-carrying slides or plungers bearing laterally on the work and mounted on a fixed support, and a centeringchuck mounted on a longitudinally-movable slide, as and for the purpose described.

5. I11 an electric metal-working apparatus,

the combination, with a contact plunger or rod adapted to move laterally toward the work, of a spring for forcing the same against the work and a cam-plate for disengaging it, as and for the purpose described.

6. In an electric metal-working apparatus, the combination, with two or more currentcarrying electrodes working in transverse lines to engage and disengage the work, of a cam-plate for moving said plungers outward away from the work, as and for the purpose described.

7. In an electric metal-working apparatus, the combination, with the secondary for the transformer, of a block 7 at the terminal thereof, and a series of plungers 13, mounted therein and bearing laterally upon the work, as and for the purpose described.

8-. In an electric metalworking apparatus,

the combination, with the block or bearing 7, of the plungers 13,working in the same, springs 14 for pressing the same inward, and a camplate 16, engaging with pins projecting from said plungers, as and for the purpose described.

9. In an electric metal-working apparatus, the combination, with the current-carrying electrodes bearing on the same and adapted to make rubbing or sliding contact therewith, of means for rotating the work in contact with such electrodes, as and for the purpose described.

10. In an electric metal-working apparatus, the combination, substantially as described, of a number of current-carrying electrodes consisting of reciprocating pluugers operatingin-lines converging upon the work and adapted to make sliding contact, and means for rotating the work while the plunger-s make rubbing or sliding contact therewith.

11. The combination, substantially as described, in an electric metal-working apparatus, of two rotary chucks or holders and two sets of current-carrying electrodes mounted between said chucks or holders and adapted to make sliding or rubbing contact with the work when rotated, as and for the purpose described.

12. The combination, substantially as described, of two rotary chucks or holders, means for imparting endwise movement to one of the same, and currentcarrying electrodes mounted between the chucks or holders and adapted to make sliding contact with the work when the same is moved longitudinally or is rotated.

13. In an electric metal-working apparatus, the combination, substantially as described, Of two rotary chucks or holders, means for imparting endwise movement to one of said chucks, and current-carrying electrodes mounted between said chuck and the part of the work to be heated and adapted to make rubbing or sliding contact with the work when it is given an end movement or is rotated.

1%. The combination, in an electric metalworking apparatus, of a reciprocating contact adapted to engage the work laterally and having a solid contact end, and a pipe or passage for delivering the cooling fluid against the inner side 01: the contact end, as and for the purpose described.

15. The combination, in an electric metalworking apparatus, of an electric contact, a piston for forcing the same against the work, a hollow stem or support extending from the piston and carrying said contact, a passage from the rearof the piston, whereby a coolingfluid employed in operating the piston may be broughtto bear upon the contact, and pipes or passages for withdrawing'thc fluid from the hollow stem or support.

Signed at Lynn, in the county of Essex and State of Massachusetts, this 1st day of August, A. D. 1890.

IIERMANN LEM I. lVitnesses:

JOHN W. GIBBONY, DUGALD MoKILLor. 

